Discharge device, base, and method



July 26, 1949-. W.'MAKENNY v DISCHARGE DEVICE, BASE, AND METHOD FiledMay 8, 1945 WA///// M014 M A/ 4 R N Y Em i-MM M w w 7 4 W Y. 5 B Y W HPatented July 26, 1949 2,477,340 DISCHARGE DEVICE, BASE, AND METHODWilliam Makenny, Mountain View, N. J assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication May 8, 1945, Serial No. 592,696

9 Claims. 1

This invention relates to discharge devices, and more particularly tothose having elongated envelopes with a base at each end.

The principal object of my invention, generally considered, is toprovide an improved form of base for the ends of elongated dischargedevices.

Another object of my invention is to provide a single-contact base forthe end of a tubular discharge device, said base comprising a shell ofinsulating material suchas a phenolic condensation product, of whichBakelite is typical, having a relatively large, generally-cylindricalflange for receiving the endportion of the envelope of said device, and2:. lug or extension with a tapered hole for guiding a lead from saiddevice to a contact ferrule at the end of said lug.

A further object of my invention is to provide a base for a dischargedevice comprising an insulating shell having a lug, and an end contactmember associated with said lug, and applied as by snapping over a beadon the end thereof or embedded in said end portion as a lining for alead-receiving aperture.

A still further object of my invention is to provide a base for adischarge device, said base being formed of Bakelite or the like, with ametal contact ferrule at the endthereof, said Bakelite being stabilizedin dimensions by after baking. so as to insure that the ferrule willstay securely aflixed.

Other objects and advantages of the invention will become apparent asthe description proceeds.

Referring to the drawing:

Fig. l is a fragmentary elevational view of a discharge lamp embodyingmy invention.

Fig. 2 is an enlarged fragmentary elevational view of the end portion ofthe envelope of such a lamp with which a base, embodying my invention,is associated.

Fig. 3 is a fragmentary view, corresponding with Fig. 2, but furtherenlarged and showing a metal ferrule as it is being applied to the baselug.

Fig. 4 is a fragmentary sectional view of apparatus for molding theinsulating or Bakelite portion of a base embodying my invention.

Fig. 5 is a view correspondin to Fig. 4, but showing a modification.

Fig. 6 is a fragmentary view, partly in eleva tion and partly in axialsection, of a base such as shown in Fig. 2, but modified.

Referringto the drawing in detail, like parts being designated by. like.reference characters, and first considering the embodiment of myinvention illustrated in Figs. 1 to 4, inclusive, there is shown adischarge device or lamp ll comprising an elongated envelope [2, havinga flare tube it at each end from a press M of which project leads [5 andI6 carrying an electrode device IT.

The lamp of the present embodiment is one in which a functionally singlelead member, which however may be in the form of a plurality of wires orstrands in parallel, extends to each electrode, the dischargebeinginiti-ated by voltage rather than-by thermionic emission. For thatreason, the lead wires I5 and I6 come together to a single contact,preferably brass, ferrule It on the base l9. The base shell 2|] is hereformed of insulating material, preferably "Bakelite, and has a generallycylindrical flange 2| which receives the reduced portion 22 at theconnected end of the envelope I2, and with which it is connected bycement 23. The base shell 20 has a lug 24 projecting axially therefromin a direction opposite to that of the flange 2|, that is, from thetransverse wall portion 25, which with the flange 2! forms the bottom ofa cup-shaped element. i

The lug 24 has an aperture or hole 26 extend-- ing axially and passingfrom the inner surface oi. the Wall 25 to the tip of the lug 24. Theaper ture is desirably conical or tapering, that is, decreasing fromtheinner surface of the wall 25 to a relatively small aperture at the tipof the lug 29, as particularly illustrated in Fig. 2. This allows forconvenient threadin of the lead wires 55 and it into the aperture 26,and said leads are guided by funnel-shaped inner portion 21 into themore acutely tapering outer portion 23 of the aperture, that is, thatportion beyond the outer plane of the transverse base wall 25. The outerportions of the leads I5 and I6 extend into the central aperture 29 ofthe ferrule IB, and are secured thereto in any desired manner, as bybrazing or soldering 3|.

In order to hold the metal ferrule It in place on the lug 24, saidlug'is desirably formed with a groove 32 defining a knob 33 therebeyond,and the ferrule I8 is formed with a bead 34, as by forcing the metalinwardly around the periphery, as

illustrated in Figs. 2 and 3, the inner diameter of said bead beingappropriate, as compared with the outer diameter of the knob33, afterfully curing or after-baking to stabilize the dimensions thereof, sothat when the ferrule is forced over the knob, fromthe position of Fig.3 to that of Fig. 2, the bead stretches sufliciently so that it slipsover the knob and snaps into place in the flared groove 32, asillustrated in Fig. 2, the peripheral edge portion 35 of the ferrule atthe same time beingpressed over lug portion 36, inward- 7 Inches Outerdiameter of theknob .258 to .260

Inner diameter of the bead .245 to .250

Inner diameter at the groove'in lug .245 to .24?

Diameter of lug at base a a .296 to. .298 Normal inner diameter offerrule adjacent rim 292th, .294

It will, therefore, be seen thatthe stlf fih llg DI". the bead over theknob may amount to from .008 to .015 inch and the stretching of theperiphery of the ferrule over the base portion of the, lug may amount tofrom .002 to .006 inch. All of these dimensions are on the assumptionthat the Bake lite shell is either fully cured in; the mold orafter-baked, so as to cure to set it sumciently that no appreciablecontraction occurs after as sembly with the ferrule.

In Fig. 4 are illustrated. parts of apparatus for molding the Bakeliteshell. This apparatus comprises a lower mold portion 38, an upper moldportion or plunger 39 and an aperture-forming inset ll. For removing theformedshell a knockout pin 432 is provided, which during the moldioperation forms the extreme bottom portion of the mold From aconsideration of this mold will be seen that the bottomportion- 3% isformed as a single piece, not counting the knock-out pin 42, the uncuredselected plasti'cor Bakelite being placed therein and squeezed by theplunger parts 3 9 and, All to entirely fill the space between them andthe mold bottom, as illustrated. After partial curing in the mold bysuitable heating. the upper portionssl ands I rise, followed by'upwardmovement of the knock-out pin 42 to remove the formed shell l9 from. themold, the material of said shell being sufficiently resilient at thattime, so that the knob portion 33 is squeezed to pass through thebeadportion 53' of the lower mold section 33, and then springs back toapproximately the original size. After removal from the mold, the shellsiii are fully cured bylafter-baking, the following time-temperaturerelationship; that is, holding at a curing temperature of 175 C. forhours, having been found suitable for "Bakelitef Instead of making theshell then press-fitting'the metal contact portion thereover. saidcontact portion or ferrule may be incorporated with the shell during theprocess of molding. Such an embodiment is illustrated in Fig. 5 in whichthe ferrule :8 is placed in the lower mold element 38*, generally likethe portion 38. of the embodiment illustrated in Fig. 4. The uncuredselected plastic or- Bakelite is placed in said ferrule and portions ofthe mold not occupied thereby, and squeezed by the plunger parts se andAl to entirely fill the space between them and the mold bo-tto i andsupported ferrule is It will be seen that while the ferrule l8- isdesirably like that of the preceding embodiment and provided with a bead34 the lower mold portion 38 6s unprovided withan interfitting bossportion, sothat after the plastic has been pressed in thefmold andferrule, and suff ciently cured, the formed base may be removed byraising the mold upp rportions 39 and H followed by upward movemento'ftheknock-out pin 42 In of the base, and

i such as illustrated in, Fig. 4,

the case of this embodiment, the Bakelite or other plastic is desirablycured in the mold, so that there is no shrinkage thereafter with respectto the ferrule, although it may if desired, be removed to anothercontainer for finishing the curing operation, as in the firstembodiment.

Referring now to the embodiment of my invention illustrated in Fig. 6,there,- is shown a shell I9 which may be formedlike the shell IQ of thefirst embodiment, except that a metal, preferably brass, ferrule [8shaped with an outstanding inner flange 44, as well as the outer flange45 on the body portion 4.6-. is placed in the bottom of a mold, prior tointroduction of he Bakelite or other moldable material. When, the;plunger descends, the ferrule H3 is molded in place in the plasticmaterial, as illustrated, thereby avoiding the necessity of pressfitting an exterior ferrule, as in accordance with the first embodiment.

As a further embodiment a ferrule. such as designated by the referencecharacter [8 in the. preceding embodiment,,may be formed without aninner flange, such as that there designated 44, and pressed in place inthe formed shell, after the latter has been suflicientiy cured, ratherthan being embedded in the plastic material to form it while in thebottom of the lower mold element,

From the foregoinggit will be seen that I, have devised an improved formof base for discharge. devices, such as fluorescent and other lamps. Itwill be understood that although the diameter of the flange on they basewhich is secured to the adjacent end of the lamp envelope may be changedto agree with a change in the diameter of the envelope, the lugportionand associated ferrule may be constantfor all eischarse devices of thisgeneral type, thereby adapting such lamps for use with sockets ofuniform character.

Although preferred embodiments of my invention have been disclosed, itwill be understood that modifications may be made within the spirit andscope of the appended I claim: I

l. A discharge device comprising an. elongated envelope and a base,said. base comprising a shell. of moldable insulating material with, agenerally cylindrical flange receiving and. secured to an end portion ofsaid envelope and a lue extendin axially therefrom in a directionopposite to. that of said flange, said lug having a hole receivin a l adf om said device and formed with an, ex terior roove, and a metal conact ferrule formed with an interior bead, of appropriate diameter mparedto the grooved lug, and secured to said l by a pressed fit causing, saidhead to snap into the ve; said lead connecting with said ferrule. I

2. A discharge device comprising elongated envelope and a base, saidbase. comprisin a Bakelite shell with a, generally cylindrical flangereceiving and secured to an end portion of said envelope and a lugextending axially therefrom in a direction opp ite to hat of saidflange. said lug having a hole and formed with an exterior groovedefining an end knob with a diameter of about .259",.a lead from saidde- Vice disposed in said hole, rule formed with an interior beadwith aninto rior diameter of about-.247", and secured to said lug by a pressedfit causing said. bead to snap ov r said knob and into the. lug groove,and means connecting said lead with said, ferrule.

3. A base for a discharge device comprising a shell of moldableinsulating material with, a gem a metal contact fer a erally cylindricalflange to receive and be secured to an end portion of the envelope ofsaid device, a lug extending axially therefrom in a direction oppositeto that of said flange, said lug having a hole for receiving a lead fromsaid device and formed with an exterior groove, and a metal contactferrule formed with an interior bead, of appropriate diameter comparedwith the grooved lug, and secured to said lug by a press fit, causing,

said bead to snap into the lug groove, so that said ferrule provides acontact for connection with said lead.

4. A base for a discharge device comprising a Bakelite shell with agenerally cylindrical flange adapted to receive and be secured to an endportion of the envelope of said device, a lu extending axially therefromin a direction opposite to that of said flange, said lug having a holefor receiving a lead from said device and formed with an exterior groovedefining an end knob having a diameter of about .259 inch, and a metalcontact ferrule formed with an interior bead having an interior diameterof about .247 inch and secured to said lug by a press flt, causing saidbead to snap over said knob and into said lug groove and be thus held inplace for connection with said lead.

5. A base for a discharge device comprising a stabilized Bakelite shellwith a generally cylindrical flange adapted to receiveand be secured toan end portion of the envelope of said device, a lug extending axiallytherefrom in a direction opposite to that of said flange, said lughaving a hole for receiving a lead from said device and formed with atrunk having a diameter of about .297 inch and an exterior groovedefining an end knob having a diameter of about .259 inch, and a metalcontact ferrule formed with a rim having a normal inner diameter of .293inch, and an interior bead having an interior diameter of about .247inch and secured to said lug by a press fit, causing said rim to bepressed over said trunk and said bead to snap over said knob into saidlug groove and be thus held in place for connection with said lead.

6. A base for a discharge device comprising an insulating shell with agenerally cylindrical flange adapted to receive and be secured to an endportion of the envelope of said device and a lug extending axiallytherefrom in a direction opposite to that of said flange, said lughaving an axial hole for receiving a lead, the outer portion of said lughaving a metal ferrule lining said hole for connection with said lead.

7. A base for a discharge device comprising a shell of moldableinsulating material with a generally cylindrical flange adapted toreceive and be secured to an end portion of the envelope of said device,a lug extending axially therefrom in a direction opposite to that ofsaid flange, Said lug having a central aperture flaring from its end inthe same direction as said flange, for receiving a lead from saiddevice, formed with a trunk having a diameter of about .297 inch and anexterior groove defining an end knob having a diameter of about .259inch, and a metal contact ferrule formed with a rim having a normalinner diameter of .293 inch, and an interior bead having an interiordiameter of about .247 inch and secured to said lug by a press fit,causing said rim to be pressed over said trunk and said bead to snapover said knob into said lug groove and be thus held in place forconnection with said lead, the peripheral edge of said ferrule beingflared outwardly to facilitate starting the fitting on said lug, andsaid shell having a correspondingly formed relief groove around thetrunk of the lug, snugly receiving said flared edge portion when theferrule is in place.

8. A discharge device comprising an elongated envelope and a base, saidbase comprising a shell of moldable insulating material with a generallycylindrical flange receiving and secured to an end portion of saidenvelope, a lug extending axially therefrom in a direction opposite tothat of said flange, said lug having a central aperture flaring from itsend toward said envelope, formed with a trunk having a diameter of about.297 inch and an exterior groove defining an end knob having a diameterof about .259 inch, a lead from said device loosely disposed in saidaperture, a metal contact ferrule formed with a rim having a normalinner diameter of .293 inch, and an interior bead having an interiordiameter of about .247 inch and secured to said lug by a press fit,causing said rim to be pressed over said trunk and said bead to snapover said knob into said lug groove and be thus held in place forconnection with said lead, the peripheral edge of said ferrule beingflared outwardly to facilitate starting the fitting on said lug, andsaid shell having a correspondingly formed relief groove around thetrunk of the lug, snugly receiving said flared edge portion when theferrule is in place, and means connecting said lead with said ferrule.

9. A discharge device comprising an elongated envelope and a base, saidbase comprising an insulating shell with a generally cylindrical flangereceiving and secured to an end portion of said envelope and a lugextending axially therefrom in a direction opposite to that of saidflange, said lug having an axial hole flaring from its end toward saidenvelope, a lead from said device loosely disposed in said hole, a metalcontact ferrule lining the outer edge portion of said lug, and meansconnecting said lead with said ferrule.

WILLIAM MAKENNY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,372,007 Liarsou 8a ColumbaniMar. 22, 1921 1,568,768 Reid Jan. 5, 1926 1,643,977 Buckwalter Oct. 4,1927 1,969,777 Burke Aug. 14, 1934 2,010,037 Schulman Aug. 6, 19352,047,043 Strickland July '7, 1936 2,097,139 Wamser Oct. 26, 19372,099,056 Ferngren Nov. 16, 1937 2,117,762 Douglas May 17, 19382,135,380 Benge Nov. 1, 1938 2,177,105 Gustin Oct. 24, 1939 2,273,960Hopkin Feb. 24, 1942 2,277,326, Huss Mar. 24, 1942 3,725 Kredler Nov. 9,1943

